Various vehicles are known for use in fire fighting. Fire fighting vehicles, including aerial platform trucks, ladder trucks, pumpers, tankers, etc., often employ a turret for dispensing fire fighting agents (e.g. water, foams, foaming agents, etc.) onto areas such as fires, chemical spills, smoldering remains of a fire, or other similar areas. Such turrets typically comprise one or more arms which are extendable, rotatable, or otherwise moveable with electric, hydraulic, or pneumatic actuator systems. While fighting a fire, the turret may be moved around in a three-dimensional space by using the actuator system to move individual arms. Once a nozzle of the turret is brought to a particular position and orientation relative to a fire, a fire fighting agent may be dispensed from the nozzle and directed at the fire.
Typically, this positioning and aiming of turrets is controlled by a human operator. According to one approach, the operator positions and aims the turret using a joystick which is coupled to the turret actuators. Unfortunately, in situations where the fire produces a large amount of smoke, the turret and the precise location of the fire become obscured from an operator's view. This situation is exacerbated by the fact that the tremendous flow of water or other fire fighting agent through the turret creates forces which affect turret positioning, making it even more difficult for the operator to know the precise position of the turret. The result is that the operator is often susceptible to inadvertently causing the turret to collide with other objects, including for example the fire fighting vehicle upon which the turret is mounted. Additionally, because the operator's view of the turret nozzle as well as the fire may be severely limited, the operator's ability to control the position and orientation of the nozzle for maximum fire fighting effectiveness is also severely limited.
Further, existing turret systems are often cumbersome or difficult to operate. For example, turret systems typically allow the turret to be manually stored and locked into place to avoid damage during vehicle travel. However, the process of storing and locking the turret can be time consuming because the proximity of the turret to other equipment on the fire fighting vehicle requires that the turret be controlled with great care. Additionally, when the fire fighting vehicle arrives at the scene of the fire and the turret is first deployed, it is necessary for a fire fighter to manually deploy the turret from the stored position, thereby diverting the fire fighter's attention away from other important activities. Finally, the operator interface used to control the turret limits the operator's ability to control the turret from a variety of different vantage points and with the benefit of a variety of different views of the turret and the fire. A variety of other problems exist which relate to the difficulty and/or amount of operator involvement required to operate turrets.
Also, existing turret systems often use unreliable and/or complex systems to measure the rotary position of the turret. This problem is exacerbated by the generally large size of the turret and its relatively small range of rotation. Thus, it would be advantageous to provide an improved position sensor for a turret.
Accordingly, it would be desirable to provide a control system for a turret which overcomes one or more of the above-mentioned problems. Advantageously, such a control system would enhance fire fighter safety by increasing fire fighting effectiveness. The techniques below extend to those embodiments which fall within the scope of the appended claims, regardless of whether they provide any of the above-mentioned advantageous features.